Iraq is a clear example of how the oil reveues may be there but without the mechanism of getting the oil revenues to work creating infrastructure and jobs, and even the basic mechanism of a well functioning civil service and a financial and banking system to put the money to work, things can be quite bleak when they do not have to be. Some of it also is agreement between the communities and leadership to get a consensus on what should be done and how it should be spent. It shows how litttle can be taken for granted in war torn, civil dissension fractured places of the world, even in relatively literate and functioning societies like that of the Arab middle eastern states. See the links to this documenting the difficulties.